Contents

This document explains how to support a Point-to-Point Protocol over Ethernet (PPPoE) Client on Cisco IOS® routers connected via an Ethernet Interface to a DSL modem or the DSL customer premises equipment (CPE) of another vendor.

ISPs often provide their customers with a DSL modem that has one Ethernet interface to connect to the customer Ethernet segment, and another interface for DSL line connectivity. In such a case, the DSL modem only acts as a bridge if the CPE is not configurable for any IP connectivity or enhanced features over DSL. This limits your connectivity to only one PPPoE Client PC. With the addition of a Cisco IOS router connected to the Ethernet of the DSL modem, you can run the PPPoE Client IOS feature on the Cisco router. This can connect multiple PCs on the Ethernet segment connected to the Cisco IOS router. With the use of the Cisco IOS router, you can enhance your DSL connectivities and all IOS features, such as Security, Network Address Translation (NAT) and Dynamic Host Configuration Protocol (DHCP) to internal hosts.

The PPPoE feature allows you to initiate a PPP session on a simple bridging Ethernet connected client. The session is transported over the ATM link via encapsulated Ethernet-bridged frames. You can terminate the session at either a local exchange carrier central office or an ISP point of presence.

The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command.

Note: In this document, the PPPoE Client connection is initiated from the Cisco router. This is the Cisco 2611 router in this configuration. The Cisco 827 router in the diagram represents the non-Cisco DSL CPE.